Medical Dictionary Definitions A-Z List

Medical Dictionary Definitions A - Z - «R»:

RadonRadon: A radioactive element formed as a gas during the breakdown
of radium. ...

Raeder's syndromeRaeder's syndrome: A distinctive
syndrome of headaches, also known as cluster headache or
migrainous neuralgia. The common pattern of cluster
headache is termed "episodic" and is characterized by 1-3
short attacks of pain each day around the eyes, clustered
over a stretch of 1-2 months, follow...

RaleRale: A type of abnormal lung sound heard through a stethoscope.
Rales may be sibilant (whistling), dry (crackling) or wet (more sloshy) depending on the
amount and density of fluid refluxing back and forth in the air passages. The word rale is
a straight steal from the French rale (minus the circum...

Ramsay Hunt syndromeRamsay Hunt syndrome: A herpes virus infection of the geniculate nerve ganglion that causes paralysis of the facial muscles
on the same side of the face as the infection. The geniculate ganglion is a sensory ganglion associated with the VIIth cranial
nerve.
The Ramsay Hunt syndrome is usually ass...

Ramsay Hunt, JamesRamsay Hunt, James: Pre-eminent 20th-century American neurologist (1872-1937) who described a number of important diseases.
Including:
Ramsay Hunt paralysis: An hereditary disorder resembling adult Parkinson's disease, but less severe, characterized by myoclonus and signs of cerebellar dysfunction,...

RamusRamus: In anatomy, a branch, such as a branch of a
blood vessel or nerve. For example, the ramus acetabularis arteriae
circumflexae femoris medialis is the branch of an artery that goes to
the socket of the hip joint. The plural of ramus is rami....

Ramus of the mandibleRamus of the mandible: One of the two prominent,
projecting back parts of the horseshoe-shaped lower jaw
bone....

RandomRandom: The process by which an outcome is determined
solely by chance, for example, by a coin flip.
A randomized controlled trial is a clinical trial
that involves at least one test treatment and one control treatment
and in which the treatments to be administered are selected by a
random proce...

Random matingRandom mating: Totally haphazard mating with no regard to the
genetic makeup (genotype) of the mate so that any sperm has an equal chance of fertilizing
any egg. This rarely, if ever, occurs but the concept is important in population
genetics. Also called panmixus....

Random number tableRandom number table: A table of numbers generated in an unpredictable, haphazard sequence. Tables of random numbers are used to create a random sample. A random number table is therefore also called a random sample table. Random numbers were traditionally selected from a printed table. Today random ...